/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// API class

package org.mozilla.javascript;

/**
 * Embeddings that wish to filter Java classes that are visible to scripts through the LiveConnect,
 * should implement this interface.
 *
 * @see Context#setClassShutter(ClassShutter)
 * @since 1.5 Release 4
 * @author Norris Boyd
 */
public interface ClassShutter {

    /**
     * Return true iff the Java class with the given name should be exposed to scripts.
     *
     * <p>An embedding may filter which Java classes are exposed through LiveConnect to JavaScript
     * scripts.
     *
     * <p>Due to the fact that there is no package reflection in Java, this method will also be
     * called with package names. There is no way for Rhino to tell if "Packages.a.b" is a package
     * name or a class that doesn't exist. What Rhino does is attempt to load each segment of
     * "Packages.a.b.c": It first attempts to load class "a", then attempts to load class "a.b",
     * then finally attempts to load class "a.b.c". On a Rhino installation without any ClassShutter
     * set, and without any of the above classes, the expression "Packages.a.b.c" will result in a
     * [JavaPackage a.b.c] and not an error.
     *
     * <p>With ClassShutter supplied, Rhino will first call visibleToScripts before attempting to
     * look up the class name. If visibleToScripts returns false, the class name lookup is not
     * performed and subsequent Rhino execution assumes the class is not present. So for
     * "java.lang.System.out.println" the lookup of "java.lang.System" is skipped and thus Rhino
     * assumes that "java.lang.System" doesn't exist. So then for "java.lang.System.out", Rhino
     * attempts to load the class "java.lang.System.out" because it assumes that "java.lang.System"
     * is a package name.
     *
     * @param fullClassName the full name of the class (including the package name, with '.' as a
     *     delimiter). For example the standard string class is "java.lang.String"
     * @return whether or not to reveal this class to scripts
     */
    public boolean visibleToScripts(String fullClassName);
}
